Method and apparatus for making photomechanical printing plates



Match 23' 1926. N 1,577,442

-L. BASSANI METHOD AND APPARATUS FOR MAKING PHOTOMECHANICAL PRINTINGPLATES Fil 9 11. 1922 2 Sheets-Sheet 1 Fig.1 Fig.2 Fig.5

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i Bassan p' INVENTOR;

' Lau March 23. 1926. I 1,577,442

, L. BASSAN METHOD AND APPARATUS FOR MAKINGFHOTOMECHANICAL PRINTINGPLATES File Dec- 11, 1922 2 Sheets-Sheet 2 Lqu re r1 B95504"? iNVENTOR;

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Y 'mnon .arrmrus ron mum i no'romncmrcu. rnm'rme mam ,ap uaeo aeals-amber 11, 1922. Serial 110,666,078.

Ta all whom'it may concern: I

.Be it known that I, LAURENT BASBANI, subject of the King of Italy,residing at .CorbeiLWSeine-et-OISe, in the Republic of 6 France, haveinvented; new" and useful Im-w rovements in Methods and Ap aratus forother is obtained by means of a reticulated photographic plate, whichlatter is itself obtained in such manner that the reticulated L screenis displaced during the exposure 1n itsv own' plane, i. e. in a plane atright angles to the optical axis of the apparatus. Said known methodismore particularly'adapted or in colors. -In the caseof color.printing,- two printin "surfaces are used for eachcolor as is well. own.V

It has beendiscovered that in the case of typographic printing, thefirst printin surface mentioned above may be omitte and use is ma deonly of the second printing surface i. e. that obtained by means of thespecial reticulated photo raphic plate which is itself obtained b agisplacem'ent'of the reticulated screen uring the exposure. 1 Thepresent invention consists in a method I for photo-typographic printingaccording to which the s ngle printing surface used is obtained by meansof a reticulated photoaphic plate, which is itself obtained by isplacinthe reticulated screen in its plane 1 during t e photographic o eration.The displacement of said reticu ated screen is preferabl efiected in-adirectionat an angle with. the ines on the screen. vThe invention. alsocom risesa device which ma .be used with'a vantage for effecting anddisplacement of the reticulated 5 screen. 7

- 'In the accompanying drawing given by of example:

. wa r -1 ig. 1 shows a. portion of a reticulated crosssed at screenformed by opaque. lines One of said printing surright anglesand at 45 tothe horizontal.

Fig. 2 shows a portion of screen wherein the crossed opaque lines arevertical for one set andhorizontal for the other.

Fig.3sho'ws a portion ofscreen wherein the opaque lines are crossed atan angle of predetermined value.

Fig. 4 1s a vertical section along the broken line AA of Fig. 5, of adevice 'according to the invention. v

Fig. 5. is a section, of the same on the line B-B of Fig. 4.

Fig. '6 shows a yoke member with adjustv able setting 1 Fig. 7 is asection of the same on'the line D-D of Fig. 6.

ableyoke-members in position.

It is known that the photo-mechanical plates now used for thetypographic printing for instance of papers, magazines and the likenecessitate numerous :re'touchings' if fineness together with strengthare desired for the image. If it is desired to obtain all the details ofthe photographed object, the screen appears in the white parts of theimage, these whiteparts are impure and I The retouching the plate lacksin vigour. operation has for its main object to suppress the blackpoints left by the reticulated screen in the 'white parts 1n such manneras to purify the latter, while conserving all the plastic character ofthe late. tion must be carried out y clever workmen and is long andexpensive.

The method accordin to the present invention makes it ossib%eto do awaysubstantially with al hand made retouching and 'to re lace the latter bya very simple mechanica operation consisting in the shifting of thescreen in its plane during the exposure.

According to the invention, .the drawing, engraving, image or the actualobject is photographed by means of a screen photo- Fig-8 is a viewsimilar to Fig. 4 showing the reticulated screen as well as the adjust-The operagraphic apparatus, of the same kind asthose now on wear. If itis supposed that the exposure lasts 10 minutes, the object isphotographed in the usual .manner during sa 6 minutes, the screen isthen slightlyshi ed .in its plane and the exposure. continues during 2minutes, the screenis shifted again and the exposure carried out duringthe 2 last minutes, the above numbers-being, of course, given solely byway of. "example. It has been observed that, under these conditions, thescreen disappearsfrom the white mally used in, photo-mechanicalprocessesmay be constituted in different manners; they may beconstituted by opaque lines crossed at right angles and inclined at 45to the horizontal (Fig. 1), or by two series of opaque lines crossed atright angles whereof one series is vertical and the other horizontalFig. 2) or again,, by opaque lines crossed at any predetermined angle(Fig. 3). According to the invention, when the screen has the form shownin Figs. 1 and 3, said screen will be moved preferably eitherhorizontally or vertically; when the screen has the form shown in Fig.2, it will be displaced preferably in the direction at 45 to thehorizontal.

the desired places. The displacement of the screen ma be obtained byusing the device shown in Tigs. .4 and 5. Said device comprises a frame1 upon which are secured the supporting journals 2, 3, 4. This frame 1sprovided with a sleeve part 5 ending in a support 6'whose upper end 7is'fork-shaped and engages the collar 8 of the driving pinion 9 of thedevice.

The frame 1 is itself secured to a carriage movable in the horizontaldirection and generally disposed in all the photographic apparatusconstructed for the use of screens in photo-mechanical processes. Theframe 1 can be therefore movedhorizontally with said carriage in theconditions required to permit the execution of the usual photographicoperations. 1

A shaft 10 which turns in the sleeve 5 is provided at one end with aneccentric collar 11 and at the other end has a pinion 12 keyed thereonengaginga pinion 13 which turns on a stud shaft 14 and engages thedriving pinion 9. The driving pinion 9 is mounted on the shaft 15 by aslidin key arrangement which permits the lengt hwise movement of. pinion9. along said shaft.

A casing 16 disposed upon the rear,..part of the apparatus serves asasupport for the shaft 15 which turns in the bearings Hand 18. Thisshaft is rovided at one end with a sto ring-'19 an at the other. endwith a 'mille' head 20 carrying a pointer '21. By

' ring 17.

Such displacement will en- 7 sure the perfect suppression of the screenat means of said pointer 21 the different angular positions of the head20 may be read from graduations' provided on the face of the bearin 17..

The device comprises also another frame 21 which is in relation with theframe 1 by means of the yoke members 22, 23, 24, 25

disposed at 45 and which embrace the jour nals 2, 3, 4 andthe collar 11,respectively.

On the frame 21 are suitably secured the usual necessary bars supportingthe reticulatedscreen which is thus displaced at the same time as saidframe 21.

The operation is as follows: When the milled head 20 is actuated, theeccentric collar 11 isrotated by means of the pinions 9,

13,12. This operation is effected from the outside of the apparatusirrespectively of the position occupied in the horizontal direction bythe supporting frame 1. The angular displacement of the eccentricjournal 11 effects, by means of the yoke members 25, the displacement ofthe frame 21, which, guided by the journals 2, 3, 4 will move accordingto the direction of the yoke members 22, 23, 24, the amount of thismotion being determined by the position of the pointer 21 on thegraduated face of the It is advantageous that the direction of thedisplacement of the screen may be changed if desired. This result isobtained by mounting the yoke members "in such manner that their angularposition may be adj usted with respect to the frame 21,-as shown in Fig.8. These yoke members may be of the form shown in Figs. 6 and 7; theyare provided with holes 26 which are adapted to engage correspondingpivots 27 secured to the frame 21 the yoke members shown. at 22', 23',24', 25 in Fig. 8 are thus adapted to swing on the pivots 27 so as to beplaced in the proper direction. They are then secured to the frame 21 byscrews 28 which extend through arcuated slots 29 and screw into tappedholes in the frame 21.

Various constructional modifications in detai. may be obviously made inthe device described without departing from the invention. 9

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is: a

1. A method for preparing printing surfaces for photo-typographicprinting which consists in reproducing upon the surfaces to be preparedreticulated photographic plates obtained by the displacement of thescreen in its plane during theexposure.

2. A method for preparing printing surfaces for photo-typographiepnntingwhich consists in reproducin upon the surfaces "to be preparedreticulate photographic plates obtained by the displacement of thescreen in its plane during the exposure, in-a direc-v opaque lines otion at an angle with the direction of the said screen.

3. A method for photo-typographic printing which consists in printingeach image by means of'a single reticulated printing surface obtained bymeans of a reticulated photographic plate, itself obtained by shiftingthe screen in its plane during the exposure.

4. An adjusting device for photographic cameras comprising, a supportingframe movable in a direction at right angles to its plane, a reticulatedscreen, a screen holder parallel to said supporting frame, an

engagement with the screen holder and adapted to displace the same inits plane, means for rotating said eccentric member in all positions ofthe supportin frame, guiding means onsaid supporting rame for guidingthe screen holder in a certain di-.

rection and adjusting means forvarying the angular position of saidguiding means.

6. An adjusting device for photographic cameras, comprising a supportingframe movable in a direction at right angles to its plane, a reticulatedscreen, a screen holder parallel to said supporting frame, anactuatingshaft parallel to the above stated direction, indexing means forascertaining the angular position of said shaft, a pinion splined onsaid shaft, an adjusting shaft rotatably mounted in the supportingframe, toothed wheels for operatively connecting said adjusting shaft tosaid pinion, an eccentric part on saidadjusting shaft, in engagementwith the screen holder and adapted to displace the same in its plane,guiding pins on the supporting frame, and yoke members on the screenholder having slots 4 in which said pins are engaged respectively. 7. Anad usting device for photographlc cameras, comprising a supporting framemovable in a direction at right angles to its plane, a reticulatedscreen, a screen holder parallel to said supporting frame, an actuatingshaft parallel to the above stated direction, indexing means forascertaining the angular position of said shaft, a pinion splined onsaid shaft, an adjusting shaft ro-- tatably mounted in the supportingframe toothed wheels for operatively connecting said adjusting shaft tosaid pinion, an eccentric part on said adjusting shaft, in engagementwith the screen holder and adapted to displace the same in its plane,guiding pins on the supporting frame, yoke members on the screen holderhaving slots in which said pins are engaged respectively and means foradjusting the angular pos1- tion of said yoke members upon thescreenholder.

In testimony whereof I have signed my name to this specification.

LAURENT BASSANI.

